Foundation Dynamic Soil Impedance Calculator

Structural dynamics & earthquake engineering: Calculate Gazetas dynamic foundation impedance functions—static stiffness ($K$), dynamic stiffness modifier ($k(\omega)$), and radiation damping ($C$)—for surface footings.

Foundation Geometry & Vibration Mode

Footing Half-Width B (m): Total width = 2B = 10 m

Footing Half-Length L (m): Total length = 2L = 20 m

Vibration Mode:

Excitation Frequency f (Hz):

Subsoil Elastic Half-Space

Shear Wave Velocity V_s (m/s):

Soil Density ρ (kg/m³):

Soil Poisson's Ratio ν:

Dynamic Impedance Output: K + i·ω·C

Dynamic Stiffness K:

MN / m (spring)

Radiation Damping C:

MN · s / m (dashpot)

Shear Modulus G:

MPa

Dimensionless a₀:

ω B / V_s

Damping Ratio β_s:

ω C / (2 K) %

Static Benchmark Stiffness ($K_{static}$)

Zero-Frequency Static Stiffness: --

Dynamic Modifier Factor $k(omega) = K / K_{static}$: --

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Foundation Dynamic Soil Impedance Calculator

Foundation Geometry & Vibration Mode

Subsoil Elastic Half-Space

Dynamic Impedance Output: K + i·ω·C

Static Benchmark Stiffness ($K_{static}$)

Frequently Asked Questions